title: β-Elemene enhances susceptibility to cisplatin in resistant ovarian carcinoma cells via downregulation of ERCC-1 and XIAP and inactivation of JNK.
abstract: β-Elemene is a promising new plant-derived drug with broad-spectrum anticancer activity. It also increases cisplatin cytotoxicity and enhances cisplatin sensitivity in resistant human carcinoma cells. However, little is known about the mechanism of its action. To explore the potential therapeutic application of β-elemene as a drug-resistance modulator, this study investigated the underlying mechanism of β-elemene activity in cisplatin-resistant ovarian cancer cells. β-Elemene enhanced cisplatin sensitivity to a much greater extent in chemoresistant A2780/CP70 and MCAS human ovarian carcinoma cells compared to the chemosensitive parental cell line A2780. The dose-modifying factors for cisplatin were between 35 and 60 for A2780/CP70 cells and between 1.6 and 2.5 for A2780 cells. In the cisplatin-resistant ovarian carcinoma cells, β-elemene abrogated cisplatin‑induced expression of excision repair cross-complementation group‑1 (ERCC-1), a marker gene in the nucleotide excision repair pathway that repairs cisplatin-caused DNA damage. In addition, β-elemene not only reduced the level of X-linked inhibitor of apoptosis protein (XIAP), but also downregulated cisplatin-mediated XIAP expression in chemoresistant cells. Furthermore, β-elemene blocked the cisplatin-stimulated increase in the level of phosphorylated c-Jun NH2-terminal kinase (JNK) in these cells. These novel findings suggest that the β-elemene enhancement of cisplatin sensitivity in human chemoresistant ovarian cancer cells is mediated at least in part through the impairment of DNA repair activity and the activation of apoptotic signaling pathways, thereby making resistant ovarian cancer cells susceptible to cisplatin-induced cell death.
authors.affiliation: National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Quentin Q
authors.initials: QQ
authors.lastname: Li
authors.forename: Rebecca X
authors.initials: RX
authors.lastname: Lee
authors.forename: Huasheng
authors.initials: H
authors.lastname: Liang
authors.forename: Gangduo
authors.initials: G
authors.lastname: Wang
authors.forename: Jueli M
authors.initials: JM
authors.lastname: Li
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Zhong
authors.forename: Eddie
authors.initials: E
authors.lastname: Reed
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002277:Carcinoma / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000008:administration & dosage; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects / Q000235:genetics; D004720:Endonucleases / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000096:biosynthesis*; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D012717:Sesquiterpenes / Q000008:administration & dosage; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D012717:Sesquiterpenes; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; C445979:beta-elemene; D048031:JNK Mitogen-Activated Protein Kinases; C071447:ERCC1 protein, human; D004720:Endonucleases; D002945:Cisplatin